Elixir in Action

385 Pages·2019·4.57 MB·English

by  Saša Jurić

SECOND EDITION
Saša Juric´
M A N N I N G

praise for the first edition
Delightful and insightful ... with a ton of practical advice.
— Ved Antani, Electronic Arts
Outstanding coverage of Elixir’s distributed computing
capabilities, with a real-world point of view.
— Christopher Bailey, HotelTonight
Read this book if you want to think and solve problems in the Elixir
way!
— Kosmas Chatzimichalis, Mach 7x
Functional programming made easy.
— Mohsen Mostafa Jokar, Hamshahri
Probably the best introduction to Elixir and the Functional
Programming.
— Amazon customer
A good book for experienced programmers who want to learn more
about Elixir.
— Amazon customer

Elixir in Action
Second Edition
SAŠA JURIC´
MANNING
Shelter ISland
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1 2 3 4 5 6 7 8 9 10 – SP – 23 22 21 20 19 18
brief contents
1 ■ First steps 1
2 ■ Building blocks 16
3 ■ Control flow 63
4 ■ Data abstractions 102
5 ■ Concurrency primitives 129
6 ■ Generic server processes 159
7 ■ Building a concurrent system 179
8 ■ Fault-tolerance basics 201
9 ■ Isolating error effects 224
10 ■ Beyond GenServer 251
11 ■ Working with components 277
12 ■ Building a distributed system 305
13 ■ Running the system 334
v

contents
preface xiii
acknowledgments xv
about this book xvii
about the author xxi
about the cover illustration xxii
1 First steps 1
1.1 About Erlang 1
High availability 3 ■ Erlang concurrency 3
Server-side systems 5 ■ The development platform 7
1.2 About Elixir 8
Code simplification 9 ■ Composing functions 12
The big picture 13
1.3 Disadvantages 13
Speed 14 ■ Ecosystem 14
2 Building blocks 16
2.1 The interactive shell 17
2.2 Working with variables 18
2.3 Organizing your code 20
Modules 20 ■ Functions 21 ■ Function arity 25
Function visibility 26 ■ Imports and aliases 27
Module attributes 28 ■ Comments 30
vii
vviiiiii contents
2.4 Understanding the type system 30
Numbers 30 ■ Atoms 31 ■ Tuples 34 ■ Lists 35
Immutability 38 ■ Maps 41 ■ Binaries and
bitstrings 43 ■ Strings 44 ■ First-class functions 46
Other built-in types 49 ■ Higher-level types 50 ■ IO lists 54
2.5 Operators 55
2.6 Macros 56
2.7 Understanding the runtime 57
Modules and functions in the runtime 57 ■ Starting
the runtime 59
3 Control flow 63
3.1 Pattern matching 64
The match operator 64 ■ Matching tuples 64
Matching constants 65 ■ Variables in patterns 66
Matching lists 67 ■ Matching maps 68 ■ Matching
bitstrings and binaries 69 ■ Compound matches 71
General behavior 72
3.2 Matching with functions 72
Multiclause functions 73 ■ Guards 76
Multiclause lambdas 78
3.3 Conditionals 79
Branching with multiclause functions 79 ■ Classical
branching constructs 81 ■ The with special form 83
3.4 Loops and iterations 86
Iterating with recursion 87 ■ Tail function calls 88
Higher-order functions 91 ■ Comprehensions 95 ■ Streams 97
4 Data abstractions 102
4.1 Abstracting with modules 104
Basic abstraction 104 ■ Composing abstractions 106
Structuring data with maps 107 ■ Abstracting with
structs 108 ■ Data transparency 112
4.2 Working with hierarchical data 114
Generating IDs 115 ■ Updating entries 117 ■ Immutable
hierarchical updates 119 ■ Iterative updates 121
Exercise: importing from a file 122